Comparative biological study between quinazolinyl-triazinyl semicarbazide and thiosemicarbazide hybrid derivatives.

Practical synthesis and biological activities of quinazolinyl-triazinyl semicarbazides (10a-j) and quinazolinyl-triazinyl thiosemicarbazides (11a-j) have been described. The novel semicarbazides and thiosemicarbazides were prepared by condensation of different nucleophiles like isocyanate and isothiocyanate by the displacement of chlorine atoms on the basis of functionality concept on varying conditions. The synthesized quinazolinyl-triazinyl semicarbazide and thiosemicarbazide derivatives were evaluated for their expected antimicrobial activity. All the final synthesized derivatives were characterized by their melting point, mass spectra, H NMR and C NMR as well as elemental microanalysis. The final analogues were then analyzed for their in vitro antimicrobial activity against bacteria (Gram positive and negative) and fungus using the agar streak dilution method as well as in vitro anti-HIV activity against two types of viral strains, viz. HIV type I (III) and type II (ROD) by using MTT assay method. SAR and HOMO-LUMO studies were also carried out for proving the structural biological activity. Among them, compounds 10e, 10f, 11h and 11j gave best results as their energy gap is very low which makes their activity higher.